The coverage dependence of the one-dimensional collective diffusion coefficient was analyzed by using the gradient expansion of the local density. The transition probabilities were written as an expansion of the probabilities of the occupation configurations. Since the detail balance principle determines only a part of the diffusion terms in the expansion, different functional relations were proposed for these terms. The diffusion coefficient was obtained for various choices of these relations. However, some of them seem to be not physically sound and the diffusion coefficient does not behave properly. The range of validity of various expressions for the jump rates was determined and phase diagrams were shown. Besides that, it was shown that the transition state theory guarantees physically suitable behavior of the coefficient of one-dimensional diffusion.

One-Dimensional Diffusion: Validity of Various Expressions for Jump Rates. S.J.Manzi, G.A.Ranzuglia, V.D.Pereyra: Physical Review E, 2009, 80[6], 062104